The present invention relates to digital oscilloscope circuitry and particularly to a method and apparatus for more accurately portraying an interpolated signal with fast edges on a digital oscilloscope.
Digital oscilloscopes employing a sin(x)/x interpolator or the like for use on band limited signals have a problem with false ringing appearing on the edges of square-waves and other aliased signals with fast edges. While signals that have dominantly sine wave content will be accurately interpolated, the same interpolation method is not nearly as satisfactory for waveforms with fast rise times or fall times. It is possible, of course, for the oscilloscope to display only the stored samples which are generated according to the digital process without interpolation. However, it would be desirable to provide a substantially continuous signal trace without gaps, especially at magnified sweep speeds, without the overshoots caused by ringing.